Tests begin on propane supplies

An independent examiner has begun testing supplies of propane in Massachusetts to make sure they contain a chemical that gives a distinctive smell to the normally odorless gas, enabling homeowners to detect possible leaks.

The move comes after Attorney General Martha Coakley announced earlier this month that some deliveries of propane in Massachusetts did not contain the chemical. That investigation came after a fatal explosion in July at a condominium development in Norfolk.

The state fire marshal found a propane leak caused the blast that killed a construction worker. Other workers said they did not smell a leak. The propane was delivered from a facility in Westfield, owned by DCP Midstream LLC, headquartered in Denver.